Maynard, MA, USA: Beacon-Villager newspaper column on local history, observations on nature and recreational activities, plus an occasional health-related article. Columns from 2009-11 collected into book "MAYNARD: History and Life Outdoors." Columns from 2012-14 collected into book "Hidden History of Maynard." - David A. Mark

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Wednesday, March 2, 2016

Black Squirrels in Masschusetts

Eastern gray squirrel (internet downloaded photo)

There are 285 species of squirrels in the world, ranging in
size from African pygmy squirrel to Alpine marmot - a ground dweller about
twice the size of its American marmot relative, the woodchuck. The extended
family includes about 45 species of flying squirrels and 15 species of marmots.

Eastern Massachuetts is host to five species, in size from smallest to
largest: eastern chipmunk, southern flying squirrel, red squirrel, gray
squirrel and woodchuck. Each of these occupies an overlapping ecological niche,
so they co-exist without competing too much for habitat or food. Two hibernate
(chipmunk, woodchuck), while the other three get by on a combination of cached
food and what can be found in winter - nuts and seeds, but also leaf buds at
the tips of branches.

North American red squirrels are 1/2 to 2/3 the size
of gray squirrels (internet downloaded photo)

Over-wintering gray squirrels create insulated nests either
by making a leaf ball in the fork of a tree (the structure is called a drey) or
inside a hollow tree trunk. Or inside an attic, which for them is squirrel
heaven - warm, dry, safe from predators, and if they get bored, there may be
electric wires to gnaw on. Each year, thousands of building fires are
attributed to squirrels, rats or mice gnawing on wiring. Anyone suspecting they
have a squirrel problem should contact a professional pest control company
without delay.

The eastern gray squirrel species comes in three color variations:
gray, black and in-between, the last from getting genes from one gray and one
black parent. Black is more common in the deep woods of northern U.S. and Canada, while the gray coloration
prevails in less wild territory. The thinking is that color helps squirrels
avoid predation by eagles, hawks and owls - black better in the shadows of deep
forest while gray preferred in terrain with more daylight.

Woodchuck. Although they are ground and underground
dwellers, can also climb trees. Click on photos to enlarge

Individuals do not appear to show a mating preference based
on color. Yet there are examples of black replacing gray in suburban areas. There
is speculation that in addition to the camouflage benefit, black squirrels
displace gray squirrels because of more aggressive behavior, or because genes
adjacent to the color genes code for a more effective immune system, or because
dark hair helps capture more heat from winter sunlight, thus helping with
survival. None of these theories have been proven or disproven.

The gray of a gray squirrel is actually a mix of colors. Each
hair follicle starts hair growth, continues for a set period, then stops. After
a while the hair detaches and the follicle starts again. The process is ongoing
all year, but there are bursts of hair growth in the fall, to create a warmer
winter fur, and again in the spring when the winter coat is shed. Each hair
starts growing as white (without melanin color). Stomach hairs stay white. As face,
back and leg hairs continue to grow, most of the follicles will change to
producing a brown/orange tone or else black. The combined effect is a gray coat,
but with brown/orange tones more evident on face and tail. A mutation in the
DNA that codes for control of hair color causes all hair to start as black and
stay black, resulting in all-black squirrels.

Black variant of eastern gray squirrel (internet downloaded photo)

Gray squirrels are predominant in most of Massachusetts. However, Westfield,
MA, a bit west of Springfield, was the site of a deliberate
introduction of black squirrels about sixty years ago. The founder population
of less than a dozen proved to be successful, as part of central Massachusetts as far away as Amherst now have a sizable black squirrel
populations. Sightings are rarer farther east, but there are many confirmed
sightings in Stow
and in Maynard (the latter, most recently behind buildings on Railroad Street).

Other mammal species have black variants. The South and
Central American jaguar has a yellowish/brown coat with dark blotches, but
about five percent have a near-black melanism and are known as black panthers.
(Interestingly, the North American cougar, also at times referred to as a
panther, does not have a melanistic variant.) North American gray wolves also
exhibit melanism.

For both predators, the darker color is linked to better
hunting success from better camouflage. Dark wolves are more common is deep
forest and less common in tundra or broken forest habitat. While wolves do not
(presently) inhabit Massachusetts, it's nice
to be able to see a black squirrel in Stow
or Maynard and be reminded of the larger world.

And if one was living in India, might perchance spot a
Malabar giant squirrel - weight about four pounds, nose
to tip of tail exceeding three feet. (internet photo)

Squirrels are omnivores. In addition to nuts, seeds, leaf and flower buds, squirrels also eat insects, bird eggs, baby birds, etc. Winter storage of food - primarily nuts and bulbs - is by scattered hoarding. This means each item buried individually, but within the territory of the squirrel. Recovery is by remembering the general area and then using sense of smell to decide where to dig. In contrast, chipmunks do cache hoarding, with large amounts of seeds stored in one place. Squirrels will dig up and rebury small flowering bulbs such as crocus and snowdrop, but usually do not dig deep enough to get to tulips and daffodils. American gray squirrels are an invasive species in England, Ireland and parts of continental Europe - displacing the native red squirrels through a combination of competition for food and introduction of squirrelpox virus.

P.S. 'Gray' is the preferred spelling in the U.S. while 'grey' is preferred in Europe.

2 comments:

Thank you for sharing this knowledge. If you’ve ever been interested in hunting, then they say that it’s always a good idea to start small. Animals can be extremely hard to hunt, and starting off small will help you develop your aim and not worry about getting it wrong the first time. See more http://survival-mastery.com/skills/scouting/squirrel-hunting-tips.html

Mark - I fish (well, used to), but having grown up in a non-hunting, non-gun family, never came round to hunting. Being the curious person I am, I ended up looking at videos of how to skin, gut and cook squirrels. Still not inclined to hunt, but nice to know the information is out there.